This invention relates to a light-sensitive silver halide photographic material which provides high contrast image, more particularly, to a light-sensitive silver halide photographic material improved in problems in contrast increasing technique caused by using a hydrazide compound.
In recent years, in the fields of printing and photomechanical process, colorination or complication of the printing material has remarkably been progressed. Therefore, demands for improvement in quality and stabilization of quality of a light-sensitive silver halide photographic material for printing (hereinafter referred to as "light-sensitive printing material") which is an intermediate medium of printing have been increased year by year. Heretofore, the general light-sensitive printing material has been provided the so-called "lith-phenomenon" processing suitability in order to accomplish high quality. However, in the "lith phenomenon", it has been well known for a person skilled in the art that it is symstematically impossible to contain high concentration sulfite ion which is a preservative in a developing solution so that stability of the developing solution is remarkably inferior.
As the technique for overcoming unstability of the "lith phenomenon" and obtaining a high contrast image which is the same as the "lith phenomenon", attempts have been done as disclosed in some patent documents. For example, there has been disclosed the technique of obtaining a contrast increased image using hydrazine compounds in Japanese Provisional Patent Publications No. 16623/1978, No. 20921/1978, No. 20922/1978, No. 49429/1978, No. 66731/1978, No. 66732/1978, No. 77616/1978, No. 84714/1978, No. 137133/1978, No. 37732/1979, No. 40629/1979, No. 52050/1980, No. 90940/1980 and No. 67843/1979, etc. In the processing methods of the methods for forming an image using these hydrazide compounds, it is necessary to use a pH value of the developing solution containing the hydrazide compounds or a pH value of the processing developing solution of a light-sensitive photographic material containing the hydrazide compounds which is high to obtain high contrast image, but the technique involves the problem that high pH value decreases effective lifetime of the developing solution.
To the contrary, in Japanese Provisional Patent Publication No. 10644/1981, there is described that by containing a hydrazide compound and a development accelerating amount of an amino compound during image formation, a high contrast image can be formed with a relatively low pH (11 to 11.5).
These image forming methods using the hydrazide compound can obtain extremely high contrast images. In general, unless suitable replenishment of a development replenishing agent is supplied to a photographic processing solution, fog, etc which are not preferred for photographic performances, will be caused. However, in the method of using the hydrazide, even when exhaustion of the photographic processing solution is not so remarkable, at an undeveloped portion, for example, generation of black dots (hereinafter referred to as "pepper fog") such as black sesame between halftone dots during screen photographing using a contrast screen of the light-sensitive printing material can be observed so that it sometimes causes serious defects on commercial values. In the previously mentioned Japanese Provisional Patent Publications No. 16623/1978 and No. 20921/1978, generation of fog including the aforesaid pepper fog is restrained by adding benzotriazole as a restrainer in a silver halide photographic emulsion, but the effect is insufficient and yet high contrast property is sometimes lost, and thus it cannot be said to be a completed technique.